Oxide powder and method for preparing the same, and product using the same

Abstract

Firstly, a powder matrix is kept in a fluent state, said powder matrix consisting of a first oxide having an absorbed water amount of 0.1 to 50%, an averaged particle diameter of 0.005 to 0.5 mum and a surface hydroxyl group number of 0.1 to 25 mumol/m2. Then, one or both of a halide and an alkoxide including metal or semi-metal identical with or different from the metal or semi-metal constituting said first oxide is allowed to contact with said powder matrix kept in the fluent state, by means of an inert carrier gas, and then they are heated at a temperature of from 25 to 800° C., to thereby coat said powder matrix by a coating layer consisting of a second oxide. Further, a reaction by-product consisting of one or both of a hydrogen halide or an alcohol generated by said contacting is heated at a temperature of from 200 to 1000° C. within the inert carrier gas to thereby eliminate the reaction by-product.

What is claimed is:  
     
       1. A manufacturing method of an oxide powder comprising the steps of: 
       keeping a powder matrix in a fluent state, said powder matrix consisting of a first oxide composed of one or both of a metal oxide and a semi-metal oxide, or a composite or mixed oxide from those oxides, and having an absorbed water amount of 0.1 to 50%, an averaged particle diameter of 0.005 to 0.5 μm and a surface hydroxyl group number of 0.1 to 25 μmol/m 2 ;  
       contacting, one or both of a halide and an alkoxide including metal or semi-metal identical with or different from the metal or semi-metal constituting said first oxide, with said powder matrix kept in the fluent state, by means of an inert carrier gas, and then heating them at a temperature of from 25 to 800° C., to thereby coat said powder matrix by a coating layer consisting of a second oxide; and  
       heating a reaction by-product consisting of one or both of a hydrogen halide or an alcohol generated by said contacting, at a temperature of from 200 to 1000° C. within the inert carrier gas to thereby eliminate the reaction by-product.  
     
     
       2. A manufacturing method of an oxide powder comprising the steps of: 
       keeping a powder matrix in a fluent state, said powder matrix consisting of a first oxide having an absorbed water amount of 0.1 to 50%, an averaged particle diameter of 0.005 to 0.5 μm and a surface hydroxyl group number of 0.1 to 25 μmol/m 2 ,  
       contacting, a halide including metal or semi-metal identical with or different from the metal or semi-metal constituting said first oxide, with said powder matrix kept in the fluent state, by means of an inert carrier gas, and then heating them at a temperature of from 25 to 800° C., to thereby coat said powder matrix by a coating layer consisting of a second oxide; and  
       heating a reaction by-product consisting of a hydrogen halide generated by said contacting, at a temperature of from 200 to 1000° C. within the atmosphere to thereby eliminate the reaction by-product.  
     
     
       3. A manufacturing method of  claim 1  or  2  wherein said powder matrix comprises silica, alumina or titania, or is a composite oxide or a mixed oxide comprising at least silica, alumina or titania. 
     
     
       4. A manufacturing method of  claim 1  or  2 , 
       wherein the metal element included in said halide or said alkoxide is one, or two or more of elements selected from the group consisting of transition elements of the 3A, 4A, 5A, 6A, 7A, 8, 1B and 2B families and typical elements of the 3B, 4B and 5B families in the periodic table.  
     
     
       5. A manufacturing method of an oxide powder of  claim 1  or  2 , 
       wherein said keeping step comprises the step of keeping, said powder matrix consisting of said first oxide having the absorbed water amount of 0.1 to 50% and the surface hydroxyl group number of 0.1 to 25 μmol/m 2 , in the fluent state, by supplying said powder matrix to a fluidized bed reaction apparatus ( 11 ), and by circulating atmospheric air from the below through a baffle plate ( 24 );  
       wherein said contacting step comprises the steps of adopting the inert carrier gas as a fluidizing gas, and circulating one or both of the halide and the alkoxide together with the carrier gas through the powder matrix kept in the fluent state through the baffle plate ( 24 ) to thereby coat said powder matrix by the coating layer consisting of the second oxide; and  
       wherein said heating step comprises the step of circulating the carrier gas through the baffle plate ( 24 ), to thereby eliminate the reaction by-product and to thereby discharge said powder matrix coated by said coating layer, from the fluidized bed reaction apparatus ( 11 ).  
     
     
       6. A manufacturing method of an oxide powder of  claim 1  or  2 , 
       wherein said keeping step comprises the step of keeping, said powder matrix consisting of said first oxide having the absorbed water amount of 0.1 to 50% and the surface hydroxyl group number of 0.1 to 25 μmol/m 2 , in the fluent state, by supplying said powder matrix to a fluidized bed reaction apparatus ( 11 ), and by circulating atmospheric air from the below through a baffle plate ( 24 );  
       wherein said contacting step comprises the steps of adopting the inert carrier gas as a fluidizing gas, and circulating the halide together with the carrier gas through the powder matrix kept in the fluent state through the baffle plate ( 24 ) to thereby coat said powder matrix by the coating layer consisting of the second oxide; and  
       wherein said heating step comprises the step of circulating atmospheric air through the baffle plate ( 24 ), to thereby eliminate the reaction by-product and to thereby discharge said powder matrix coated by said coating layer, from the fluidized bed reaction apparatus ( 11 ).  
     
     
       7. A manufacturing method of an oxide powder of  claim 1  or  2 , 
       wherein a relative dispersion among elements is within ±60 when analyzing elements of a population including said oxide powder as constituent ingredients of the population; and  
       wherein no more than one agglomerate of powder particles exists in 1000 powder particles of the population.  
     
     
       8. An oxide powder having an averaged particle diameter of 0.006 to 0.5 μm, comprising a powder matrix consisting of a first oxide having an averaged particle diameter of 0.005 to 0.5 μm and composed of one or both of a metal oxide and a semi-metal oxide, or of a composite or mixed oxide from those oxides, and 
       a coating layer coating the surface of said powder matrix, said coating layer consisting of a second oxide identical with or different from said first oxide,  
       wherein said second oxide of said coating layer is chemically bonded to the surface of said first oxide of said powder matrix, and the surface of said first oxide of said powder matrix is uniformly coated by the coating layer by 60% or more,  
       wherein said powder matrix has an absorbed water amount of 0.1 to 50%, and a surface hydroxyl group number of 0.1 to 25 μmol/m2, and  
       wherein the coated amount by said coating layer is 0.1 to 10 times the surface hydroxyl group number.  
     
     
       9. An oxide powder of  claim 8 , 
       wherein said powder matrix comprises silica, alumina or titania, or is a composite oxide or a mixed oxide comprising at least silica, alumina or titania.  
     
     
       10. An oxide powder of  claim 8 , 
       wherein the metal element included in said second oxide of said coating layer is one or two or more of elements selected from the group consisting of transition elements of the 3A, 4A, 5A, 6A, 7A, 8, 1B and 2B families and typical elements of the 3B, 4B and 5B families in the periodic table.  
     
     
       11. An oxide powder of  claim 8 , 
       wherein said oxide powder is provided with hydrophobidity, by surface reforming by one or both of a silane coupling agent and a silicone compound.  
     
     
       12. An oxide powder of  claim 11 , 
       wherein the silane coupling agent is represented by the following formula (1):  
       
         
           X 4−n SiR n  . . .   (1)  
         
       
       wherein  
       X is any one of a hydroxyl group, an alkoxy group and a halogen atom, R is an alkyl group having 1 to 18 carbons, and n is an integer from 0 to 3.  
     
     
       13. An oxide powder of  claim 11 , 
       wherein the silane coupling agent is represented by the following formula (2):  
       
         
           R 3 SiNHSiR 3  . . .   (2)  
         
       
       wherein  
       R is an alkyl group having 1 to 18 carbons.  
     
     
       14. An oxide powder of  claim 11 , 
       wherein the silicone compound is represented by the following formula (3):                    
       wherein  
       the substitutional group represented by R′ is any one of a methyl group and an ethyl group;  
       R″ is any one of a methyl group, an ethyl group and a hydrogen atom, or is an alkyl group including, as a part thereof, any one of a vinyl group, a phenyl group and an amino group,  
       X is any one of a hydroxyl group, an alkoxy group, a halogen atom and an alkyl group, and  
       m is an integer from 1 to 500.  
     
     
       15. An oxide powder of  claim 10 , 
       wherein said oxide powder comprises the first oxide constituting a powder matrix which is a composite oxide or a mixed oxide including silica, or including at least silica; and the second oxide constituting the coating layer including a metal element.  
     
     
       16. An oxide powder of  claim 15 , 
       wherein the second oxide constituting the coating layer is alumina, titania, zirconia or ceria.  
     
     
       17. An abrasive agent comprising an oxide powder of  claim 16 . 
     
     
       18. A slurry for chemical/mechanical abrasion comprising an abrasive agent of  claim 17 . 
     
     
       19. An oxide powder of  claim 16 , 
       wherein the adsorbed amount of an anion-source compound to said oxide powder is 150% or more than the adsorbed amount of said anion-source compound to the powder matrix.  
     
     
       20. An ink-receiving layer forming material comprising an oxide powder of  claim 19 . 
     
     
       21. An ink-jet oriented print material obtained by coating and drying a slurry of said ink-receiving layer forming material of  claim 20 . 
     
     
       22. A toner oriented additive comprising said oxide powder of  claim 11  wherein said first oxide of said powder matrix is silica, and the second oxide of said coating layer is titania. 
     
     
       23. An ultraviolet ray absorbing material comprising an oxide powder of  claim 8  wherein said first oxide of said powder matrix is titania, and said second oxide of said coating layer is any one of silica, alumina and iron oxide. 
     
     
       24. An electrically conductive powder comprising an oxide powder of  claim 8 , wherein said first oxide of said powder matrix is silica, and said second oxide of said coating layer is titania, or antimony-doped stannic oxide. 
     
     
       25. An oxide powder of  claim 9 , 
       wherein the metal element included in said second oxide of said coating layer is one or two or more of elements selected from the group consisting of transition elements of the 3A, 4A, 5A, 6A, 7A, 8, 1B and 2B families and typical elements of the 3B, 4B and 5B families in the periodic table.  
     
     
       26. An oxide powder of any one of claims  9 , 
       wherein said oxide powder is provided with hydrophobidity, by surface reforming by one or both of a silane coupling agent and a silicone compound.  
     
     
       27. An oxide powder of any one of claims  10 , 
       wherein said oxide powder is provided with hydrophobidity, by surface reforming by one or both of a silane coupling agent and a silicone compound.  
     
     
       28. A toner oriented additive comprising said oxide powder of  claim 12  wherein said first oxide of said powder matrix is silica, and the second oxide of said coating layer is titania. 
     
     
       29. A toner oriented additive comprising said oxide powder of  claim 13  wherein said first oxide of said powder matrix is silica, and the second oxide of said coating layer is titania. 
     
     
       30. A toner oriented additive comprising said oxide powder of  claim 14  wherein said first oxide of said powder matrix is silica, and the second oxide of said coating layer is titania. 
     
     
       31. An ultraviolet ray absorbing material comprising an oxide powder of  claim 9  wherein said first oxide of said powder matrix is titania, and said second oxide of said coating layer is any one of silica, alumina and iron oxide. 
     
     
       32. An ultraviolet ray absorbing material comprising an oxide powder of  claim 10  wherein said first oxide of said powder matrix is titania, and said second oxide of said coating layer is any one of silica, alumina and iron oxide. 
     
     
       33. An electrically conductive powder comprising an oxide powder of  claim 9  wherein said first oxide of said powder matrix is silica, and said second oxide of said coating layer is titania, or antimony-doped stannic oxide. 
     
     
       34. An electrically conductive powder comprising an oxide powder of  claim 10  wherein said first oxide of said powder matrix is silica, and said second oxide of said coating layer is titania, or antimony-doped stannic oxide.